EL34 identification help

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EL34 identification help

Postby TerrySmith » Sun Mar 06, 2011 12:09 pm

Here's some closeup pics of the EL34 tubes I currently have in my '70. These came in a Music Reference RM9 amp I purchased new in Dec 1992. They lasted 8 - 9 years and well over 10,000 hrs until one of them went pyro! The other 7 of them still test strong and sound excellent.

The manual said "German supplied EL34 tubes", they don't look like Siemens, those had crimped plates and the dimple on top.

Any guesses as to who made these?


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Postby Ty_Bower » Sun Mar 06, 2011 1:46 pm

Those little square, waffle edged getter pans make me think "Chinese". I've got some Chinese 6L6 with the same getters. "Went pyro!" also makes me think of Chinese tubes... dunno why? (???)

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Postby dcriner » Sun Mar 06, 2011 8:39 pm

I would think any self-respecting German manufacturer would mark its tubes "Made in Germany." Extended lifetime for any tube can be achieved by over-designing its heater - which will reduce emission. Best to test them for emissions.

Incandescent lamps, optimally designed, have a life of less than 1000 hrs. Longer life bulbs can be desgned for many times that lifetime - while sacrficing performance.
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Postby Geek » Mon Mar 07, 2011 2:31 am

Found them!!!

But you won't like the answer:
http://forums.vintageamps.com/viewtopic ... 13&t=54065

Sorry :(
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Postby TerrySmith » Mon Mar 07, 2011 8:28 am

I never would have thought they were early Sino tubes. The four I use as "guinea pigs" have been beaten to death but still test strong and still closely matched.

Thats a good link Geek, when Sylvania went to the ECG brand a lot of strange stuff happened, rebranding foriegn tubes and quality slipping on US made tubes.
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Postby dcgillespie » Mon Mar 07, 2011 11:17 am

I've got a quad of those very same tubes I bought new at a ham fest years ago. In new ECG boxes, properly marked, the whole bit. Was saving them for something special. Finally, along came a pristine HF-89. What a disappointment those tubes were! Tested them before installing them in the amp. Under full power output testing, one tube arced at startup, two had sinking power output under sustained conditions, and one was actually OK.

Ended up putting in a very nice new quad of old Tesla EL34s. Now those are some truly wonderful tubes!

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Postby TerrySmith » Tue Mar 08, 2011 11:04 am

When that one went bad in the RM-9 it was quite a fireworks display! I was playing "Long time" by Boston very loudly. Ended up having to rebuild the bias circuit, the tube fuse wasn't quite fast enough!

The replacement tubes were EHX EL34's from around 2001, about the time the EHX brand came around. They sounded really good but the mechanical noise when you turned it off was horrible. It sounded like eight beer cans being crinkled up!
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Postby TomMcNally » Tue Mar 08, 2011 11:24 am

I went to a Boston concert in Philly in the late 80's and couldn't hear
normally for about 24 hours ... now THAT was loud.

My Velleman K-4000 with 8 EL-34's crinkles too ... Svetlana tubes.
The original Tesla firecrackers went in the first few months after
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Postby EWBrown » Tue Mar 08, 2011 3:08 pm

I went to a Grateful Dead concert in Boston (At teh Boston Tea Party, Landsdowne Street) , new years eve 1969. I had never heard of them before that, a couple friends of mine convinced me to go, and the price was pretty cheap. At the time, I was home on leave from Fort Gordon, and needless to say, I was the only one there with a crew-cut =:o

I was up close to the stage (no chairs or seating, just an open floor), it was no problem to move around and gawk at all their nice sound gear, including McIntosh tube amps, home built speaker arrays, the whole "wall of sound". When they took their break, the guitar player, and drummer walked over to me and we got talking about tubes, speakers, and how I was in the Signal School in Georgia. Yes, that would have been Jerry Garcia (long before he porked out) and Pig Pen. They seemed like nice easygoing folks and not consumed by their own fame.

I can remember after that, one long haired, really stoned-out guy saying to me "wow man, you just talked to God"... :/

The sound was definitely LOUD, but also very clean and non-distorted, and not at all fatiguing to listen to (unlike my "bleeding ears" experience at an outdoors Aerosmith concert, five years later).

They had the "liquid' light show projected on the wall, and the atmosphere inside the place had a very heavy smog of certain recreational herbal substances =:o ;) (lol)

If you really want to blow up EL34s (and your eardrums at the same time) play Devo's "Whip It" at maxed-out volume. Friend of mine was doing that a few years ago, and blew up the OPT on a VTL MB450 power amp. Its eight Svetlana 6550Cs took the lickin' and kept on tickin' after teh OPT got replaced by VTL.

He sent it back to them, and they replaced the OPT at no charge except for the shipping expenses (which were fairly considerable for one of these beasties).

Apparently the OPTs had a internal insulation breakdown problem which took a few years to reveal itself. The other MB450 a few months later went through the same thing, they also replaced its OPT at no cost. They also upgraded the B+ fuses and holders, and a few other things in both monoblocks.

/ed B
Last edited by EWBrown on Sun Jun 05, 2011 1:51 pm, edited 1 time in total.
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Postby nyazzip » Sat Mar 19, 2011 10:42 pm

back in the '70s and '80s, "Made in China" may very well have been a certificate of garbage, but things have come a long way. China makes what people/markets ask for. they can and do make anything, to any standard, nowadays....i have some excellent chinese el84s, and 12ax7s...as well as a few various hand tools that kick as much arse as say Sears Craftsman or Klein... Made in China is no longer a punchline, in my opinion....
FWIW, to this day i would still rather not patronize chinese goods, but that emotion is not based on quality concerns...
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Postby Geek » Sat Mar 19, 2011 11:31 pm

The Craftsman tools are mostly made in China nowadays ;)

Funny story - $399 Craftsman drill press vs. $59 "Power Fist" drill press from Princess Auto (both 1/3HP, 5 speed) - the cast frame bore the *same* manufacturers marks. The local Sears manager was dumbfounded (lol)

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Postby EWBrown » Sun Mar 20, 2011 1:37 pm

Last winter I bought a Chinese made "Black Bull" drill press from Tractor Supply. It is decen quality, better than I expected, and it cost $149 and is as every bit as good as the Craftsman equivalent.

It also has laser "centering" crosshairs (two line-projecting laser diodes) a built in work light - I use a 60W bulb, 75 and 100 watts are way too much light. It's really speeded up my metal mangling, and with the unibit step drills, the days of wrestling Greenlee punches (up to 7/8 inch diameter) are over.

It has 16 speeds, throughh two four step pulleys, and a center "idler" pulley, it is a bit of a minor ordeal to change the RPM speeds, but I have found the best "general purpose" RPM speed so that isn't a major factor.

/ed B
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Postby Dynacophil » Sat Jun 04, 2011 2:17 pm

they don't look like Siemens, those had crimped plates and the dimple on top.

yes, they don't look Siemens, but Dimple tops were RFT made el34 that were rebranded SIEMENS. Original Siemens didn't.

afaik Siemens never produced own el34, Siemens always bought and rebranded. Made by Philips, or TFK (Ulm), even by Ei. The latest were made by RFT in GDR, which were the "dimple-tops".
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